Module 1 Materials Flashcards
What is a polymer?
Polymers are materials made of long chains of repeating molecules called monomers. By definition, polymers are large molecules made by bonding (chemically linking) a series of building blocks.
what are the properties of polymers?
polymers are:
- high strength or modulus to weight ratios - toughness
- resilience
- viscoelasticity
- resistance to corrosion
- lack of conductivity (heat and electrical)
- color
- transparency
what are the types of polymers?
Thermo-softening polymers are sometimes refered to as thermoplastics,
And thermosetting polymer, often called a thermoset,
What is viscoelasticity
viscoelasticity is the property of materials that exhibit both viscous and elastic characteristics when undergoing deformation
what are thermo-softening polymers?
AKA thermoplastic
Thermo-softening polymers are polymers that can be re-shaped into a new shape once they are heated up.
eg.
-PET, silicon, polyurethane
What are the 2 most common crystalline Metal Structure?
**BCC **(Body-Centred-Cubic) & FCC (Face-Centred-Cubic)
what is a thermosetting polymer?
a thermosetting polymer, often called a thermoset, is a polymer that is obtained by irreversibly hardening (“curing”) a soft solid or viscous liquid prepolymer (resin)
eg.
- Epoxy resin, silicon
anything that has heat ie buckets, cups , powerpoints etc
What are the five main types of ways to classify materials?
- Metals
- non-metals
- ceramics
- polymers
- composites
What are the three subsections of Non-metals?
- Ceramics,
- Polymers,
- Composites
image: Carbon fibre is a composite of carbon and Poylmer
what is a ceramic.
an inorganic non-metallic solid made up of either metal or non-metal compounds that have been** shaped **and then hardened by heating to high temperatures.
what are the properties of ceramics.
The properties of ceramics are
* hard
* wear-resistant
* brittle
* thermal insulators and electrical insulators
* nonmagnetic.
What are the three types of conductivity classifications?
- Conductor
- Semi-conductor
- insulator
What are some examples of a conductor?
Silver, Alluminium and iron (all metals)
What are two examples of Ferrous materials?
Anything with iron (Fe) in it
*Cast iron
* Steel,
* Stainless steel
* wrought iron
What are some examples of a Semi-conductor?
Silicon, germanium, gallium aresenide
A transistor is made from a semi conductor material
What are some examples of non-ferrous materials?
Metals without iron(Fe) in them, e.g. aluminum, gold, tin, brass, etc.
What are some examples of an insulator?
Plastic, glass, wood or rubber
What are the six Propeties that engineers use to identify materials?
Density, Hardness, Tensile, strength, stiffness, toughness, Ductility.
What is Ionic bonding?
The transfer of one or more molecules from a metal (usually) to a non-metal. E.g. Lithium + fluorine.
What is Covalent Bonding?
Covalent Bonding occurs between non-metals and involves the sharing of valence electrons, with a strong attraction between the nucleus and valence electrons. E.g. Hydrogen + Hydrogen
